Insurrection in Berlin Leo crushed (9)
I believe the answer is:
rebellion
'insurrection' is the definition.
(I know that insurrection can be written as rebellion)
'berlin leo crushed' is the wordplay.
'crushed' is an anagram indicator.
'berlin'+'leo'='berlinleo'
'berlinleo' with letters rearranged gives 'REBELLION'.
'in' is the link.
(Other definitions for rebellion that I've seen before include "insurgence" , "Rising" , "Uprising" , "Insurgency" , "Defiance" .)